 /*******************************************************************************
  * Copyright (c) 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.ui.internal;

 import org.eclipse.core.expressions.PropertyTester;
 import org.eclipse.ui.IPerspectiveDescriptor;
 import org.eclipse.ui.IWorkbenchPage;

 /**
  * Tests if any Perspective is open or not.
  *
  * @since 3.3
  *
  */
 public class OpenPerspectivePropertyTester extends PropertyTester {
     private static final String PROPERTY_IS_PERSPECTIVE_OPEN = "isPerspectiveOpen"; //$NON-NLS-1$

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.core.expressions.IPropertyTester#test(java.lang.Object,
      * java.lang.String, java.lang.Object[], java.lang.Object)
      */
     public boolean test(Object receiver, String property, Object [] args,
             Object expectedValue) {
         if (args.length == 0 && receiver instanceof WorkbenchWindow) {
             final WorkbenchWindow window = (WorkbenchWindow) receiver;
             if (PROPERTY_IS_PERSPECTIVE_OPEN.equals(property)) {
                 IWorkbenchPage page = window.getActivePage();
                 if (page != null) {
                     IPerspectiveDescriptor persp = page.getPerspective();
                     if (persp != null) {
                         return true;
                     }
                 }
             }
         }
         return false;
     }

 }

